Drier-kiln.



P. W. BALLARD.

DRIER KILN.

JQPPLIGATION FILED DB0. a, 1911.

www Essa@ MWA-Wilmn? IBY ll'NlTED STATES .rnrnrrr ortica.

FREDERICK W. BALLARD, OI'F CLEVELAND HEIGHTS, OHIO, ASSIGNOR T0 THESHERWIN- WILLIAMS COMPANY, OF CLEVELAND, Gil-H0, A CORPORATION F OHI. l

DRIER-EKILN.

Specication of Letters Patent.

Patented Sept. 30, 1913.

.application nea December a, 1911. .serial no. 664,546.

T0 all whom t may concern.'

Be it known that I, FREDERICK W. BAL- LAR, a citizen of th'e UnitedStates, and a resident of Cleveland Heights, county of herein explainedandthe best mode in which I have'contem-plated applying that principle,so as to distinguish it from other inventions. In the manufacture offurniture and more particularly `of einer articles of furniture, such aspianos and the like, avery considerable delay has always been involvedin the linishing o r varnishin-g process;- for a number of coats of onekind or another of oil, varnish or paint, require to be applied, afterapplication of each of which suilicient time must be allowed for suchcoat to dry before the next is puton. The `present improved drier kilnis intended to provide means whereby this drying operationmay Ibe muchfacilitated, thus correspondingly shortening the process of manufactureof furniture and articles of the kind referred to, although insuring anequally good, or even better finish than Where\ the ordinary protracteddrying in the open air is relied on.

To the accomplishment of the foregoing and related ends, said invention,then consists of the means hereinafter fully. described and particularlypointed out in the claims. The annexed drawing and the `followingdescription set forth ih detail certain mechanism embodying myinvention, such disclosed means constituting, however, but one of thevarious mechanical forms in which the principle of the invention may beused. In said annexed drawi s:.-Figure 1 is partly an end elevation anpartly a transverse vertical section of a kiln embodying my presentimprovement; While Fig. 2 is a central vert-ical 'section taken at rightangles to Fig. 1f

In the simple structural embodiment of the invention illustrated in theforegoing figures, the chamber 1, into which the articles to be driedare desi ed to be placed, is of general rectangular orm and isfurthermore arranged with a floor 2 raised above the earth or othersupporting surface, although. this is not essential. This chamber .maybe entered through a door 3, but when` the apparatus is in operation, itis closed as `hereinafter specified. Laterally of this `chamber arevertically extending chambers or passages 4, one on each side, that arevopen at their lower ends and communicate tvith said malin chamber 1nearthe floor line t-hrough openmgs 5, as also with the exterior throughother openings 6, these openings G being preferably closed by sheets 7of cheese' cloth or other filtering medium stretched there-across. Theselateral passages-4 at `their` upper ends communicate with a chamber 8that 'is located 4directly above the central lcham-ber 1 and separatedvtherefrom by a. perforated, horizontally extending partition 9,-asshown. Such communication may be had either directly by passages 10 orthrough passages 11 that'lead over receptacles in the form ofy shallowpans 12 con taining water. Strips 13 of cloth or wicking depend acrossthese latter passages into the Water in the pans, so that when airpasses therethrough it may become rela-tively humid or saturated Withmoisture.

Disposed in the lower portions of the re'- spective lateral chambers orpassages 4 are suitable heating means, preferably in the' form of coils14, through which steam or .other suitable heating medium may becirculated. Gates or doors 15 arearranged at the bottom of each lateralpassage so as to close the sameeither to the exterior, or to theinterior of the kiln, as desired or to assume its desired intermediateposition. Each set of these gates is carried by Va common shaft ,16provided with a pointer-17 at one end, so that the exact position of thegates may be indicated on a suitable indicator without the end Walls ofthe kiln. Other gates, or valves 18, on sim-ilarshafts 19, at the upperends of the passages are adaptedto directv the current of air eitherthrough the passages 11 over the pans of Water, or through the' openpassages 10, into the air chamber 8 directly above the main chamber ofthe kiln. The sition of these upper gates is likewise indicated by meansof ointers 20. The Water level in the pans, wh1ch are connected by apipe 21, is maintained constant by a float valve 22 located in inlauxiliary supply tank 23 outside of the Having thus described withsufficient detail the construction of my improved drier kiln,its mode ofoperation may be briefly set forth. Assuming the article to be driedadmit-ted to the heating coils 14, as a result of which the air in saidpassages is heated and so caused to rise. Upon reaching the top or theupper ends of the passages, thls Warm, ascending current of air isnormally passed across the pans or receptacles 1Q which contain water,as previously stated. The eifect of thus passing Warm, dry air over thesurface of this Water, or through between the strips 13, is to evaporatesome of the Water, whereby heat is absorbed, becoming latent. Thecurrent of air is accordingly not only humidified but also cooled to adegree which causes it to descend downwardly into the main chamber, thedownward flow of air being evenlydistributed by reason of the interposedperforated partition 9. Then the proper temperature has been arrived at,this being determined in general by the amount of steam admitted to theheating coils, the gates 15 may be opened more or less, as shown inFigs. 1 and 2, so as to permit a finer adjustment of the temperature andat the sam'e time to add a fresh supply of air to that contained Withinthe kiln. This .is desirable, because the operation involved is notstrictly a drying one, as the term is ordinarily used in connection withthe drying of lumber, but rather consists in the oxidation of thevarnish or other coating applied to the article. Accordingly, the airused in drying should contain its normal quota of oxygen. The presenceof a certain amount of moisture in the air used in thus drying thevarnish, or paint` on the articlel being dried, is also recognized asessential, for if the air be'too dry it has been found that the dryingoperation does not proceed satisfactorily. Such drying operation, itwill be understood does not involve the extraction of moisture, that isWater,- at all, but relates Wholly to the hardening or oxidizing actionof the air. It is also desirable that the coat of varnish be thusoxidized from the bottom up, whereas, if the air be too dry, a thin ilmon the surface is initially hardened and the coat is brittle and apt tobe checked. Accordingly I prefer t-o maintain the content of moisture inthe air, that passes over the article being dried, rather high, myexperiments indicating that best results are obtained where the air ispractically saturated.

The direction arrows on Fig. 1 indicate the general circulation of theair occurring Where the gates are arranged in the manner there shown;that is, there is a combination of outside 'and inside currents of air.Where the gate is in the position 15 (shown in dotted outline), theclrculation is all inside; While, conversely, in the position 15 anentirely fresh current of air is drawn in through openings G anddischarged through openings 5.

By the foregoing arrangement of chambers and disposition of the heatingcoils and humidii'ying means, it will be seen that such coils andhumidifying means cooperate to produce the necessary circulation of air;that is, the column of heated air ascending in the outer chambers issufficiently cooled, incidentally to its being moistened to the desireddegree, to cause it to descend through the drying chamber proper. Thusthere is no energy Wasted, but the heating coils and humidifying ormoistening means coperate in maintaining the desired circulation,without the use of any mechanical current-producing means or thecondensation of moisture from the air (Where it should remain) by meansof cooling'coils. From the drying chamber the air may pass into thelateral chambers there to be again heated and so caused to flow in thesame path as before. A careful and exact regulation, both of thetemperature and of the amount of moisture in the circulating body ofair, is rendered possible by the adjustable gates or valvespreviouslyadescribed, so that by the use of suitable indicators, such asa thermometer and hygrometer, the drying operation may be exactly andscientifically controlled.

Other modes of applying the principle of my invention may be employedinstead of the one explained change beingr made as regards the mechanismherein disclosed, provided the means stated by any of the followingclaims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as myinvention 1. In a kiln of the class described, the combination with amain drying chamber adapted to receive the article to be dried; of anauxiliary chamber communicating with the upper portion of said mainchamber: means adapted to heat the air in said auxiliary chamber,whereby an ascending current of air is created therein; and other meansabove said main chamber adapted to humidify such current of air by theevaporation of a liquid, whereby the air is cooled and caused to descendinto said main chamber independent of any agency in the latter.

2. ln a kiln of the class described, the combination with a main dryingchamber; of an auxiliary chambercommunicating with the upper portion ofsaid -main chamber; heating coils located in the lower portion of saidauxiliary chamber, whereby an ascending current of air is createdtherein; and air-humidifying means located above said main chamber andadapted to cool such current of air and thereby cause it toydescend intosaid main chamber independent of any agency in the latter.

' thereby cause it to descend into saidmain 3. In a kiln of the classdescribed, the,

combination with a main drying chamber; of an auxiliary chamber; twopassages connecting said auxiliary chamber with the upper portion ofsaid main chamber; means for optionally closing either of said.passages; air-humidifying means located in one of said passages; andair-heating means located in said auxiliary chamber,

4. In a kiln of the class described, the combination' with a main dryingchamber; of an auxiliary chamber connected at' its lower portion withthe lower portion of said main chamber and with the exterior; means forclosing one connection or the other, as desired, said auxiliary chamberbeing also connected with the upper portion of said main chamber; meansadapted to heat the air in said auxiliarychamber, whereby an ascendingcurrent of air is created therein; and other means above said mainchamber adapted to cool such'current of air and chamber. y

5 In a kiln of the class described, the combination with a main dryingchamber; of an auxiliary chamber connected at its lower portion with thelower portion of said mainchamber and with the exterior; means forclosing one connection or the other, as desired, said auxiliary chamberbeing also connected with the upper portion .of said main chamber; meansadapted to heat the air in said auxiliary chamber, whereby. an ascendingcurrent of air is created therein; and other means above said mainchamber adapted to humidity such current of air by the evaporation of aliquid, whereby the air is cooled and caused to descend into said mainchamber.

Y 6. In a liln of the class described, the

combination with a main drying chamber; of an auxlhary chamber connectedat 1ts .lower portion with the lower portion .of .said main chamber andwith the ex terior; means for closing one connection or the other, "asdesired, said auxiliary chamber being connected with the upper portionof said main chamber by two 'separate passages; means adapted to close,elther of said passages, as desired; airhumidifying means located inone of said passages; andan-heating means located in said auxiliarychamber.

'7. In a kiln of the class described, the combination .with a maindrying chamber; of an auxiliary chamber communicating with the lowerportion of said main chamberandwith the exterior; means adapted tocontrol such communication, said auxiliary chamber beingconnected withthe upper portion of said main chamber by two separate passages; meansadapted to close either of said passages, as desired; air-hu midi-.tyingmeans located in one of said passages; and air-heating means located 1nsaid auxiliary chamber.'

Signed by FREDERICK WBALLARD.

` Attested' MYRTLE K. SoHUoH,

JNO. F. OBERLIN.

me this 6th dayiof December,

